Moore, of Biloxi, lost the 2012 Democratic primary for the seat, but was named the party's general election candidate after the primary winner withdrew. Causey, of Ocean Springs, described herself as a progressive liberal Democrat.

The 4th District runs from Laurel south to the Gulf Coast, covering all or parts of 14 counties.

Neither Moore nor Causey has filed campaign finance forms.

In the Republican primary, incumbent Steven Palazzo faced former U.S. Rep. Gene Taylor plus three others.

Winners advance to the Nov. 4 general election to face independents Cindy Burleson and Ed Reich, Joey Robinson of the Libertarian Party and Reform Party candidate Eli Jackson.